Request for technical advice: 4.5V battery box, 12V conducting rail

[DameVeraLynn]

Having spent the last few days restoring some of my childhood Lego trains, I've run into a couple of problems which I hope the experts on here may be able to help me with!

 

1. 4.5V battery box (BL Item No: x488c02)

Spoiler

This particular box comes from 7722 and was originally used to power a 4.5V train motor.  The motor still works (I have tested it by connecting it to the 12V transformer with the control knob inverted) but it fails to run when connected to the battery box (filled with three brand-new rechargeable C batteries).  Does anyone have any troubleshooting advice for these battery boxes?  Can you suggest what steps I could take to try and get it working again?  Any thoughts on the best substance to use to clean the contacts?

 

2. 12V conducting rail (looks like BL Item No: 2731b)

Spoiler

This rail should transfer power to the track when connected to the 12V transformer, but fails to do so.  I've tried unscrewing the plug and replacing it with another, but that doesn't help.  Rather strangely, it also cuts the circuit when added to a loop!  My suspicion is that there's an internal fault, possibly caused by corrosion (it looks nice and clean, but I spent some time rubbing it with a model railway cleaner before testing it!)  Has anyone come across a problem like this before?

 

Many thanks in advance for any help you are able to provide!

Edited April 6, 2018 by DameVeraLynn

[DameVeraLynn]

1. 4.5V battery box (BL Item No: x488c02): success

It was remiss of me to post on here before doing a thorough search of old topics!  This brought up the following (I record them here for the future reference of people trying to solve the same problem):

• Getting a 4.5V train running
• Corroded battery wagon
• How to check non-functioning 4.5V train set?

After reading these and with a little trial and error, I have managed to get my 4.5V train working.  It was a beautiful moment as 7722 whirred into life for the first time in around three decades!  The quality and longevity of Lego continues to impress me greatly.  Thanks to the original posters.  I think the main problem was a loose connection in the socket on the side of the battery box.

 

2. 12V conducting rail (looks like BL Item No: 2731b): still no luck

Any suggestions gratefully received.  Has anyone ever disassembled one of these 'interference-free' capacitor rails?  Will the process of pulling it apart essentially destroy it?

Edited April 7, 2018 by DameVeraLynn

[Reza]

On 4/7/2018 at 2:16 PM, DameVeraLynn said:

After reading these and with a little trial and error, I have managed to get my 4.5V train working.  It was a beautiful moment as 7722 whirred into life for the first time in around three decades!  The quality and longevity of Lego continues to impress me greatly.  Thanks to the original posters.  I think the main problem was a loose connection in the socket on the side of the battery box.

I bought last summer the boxed set 182 coming with a similar 4.5V battery box. It did not work. I had also bougth 7722 from Ebay missing the battery box. After reading on how to restore and getting rid of corrosion, I worked on it for two hours. Finally I plugged-in and turned the switch and then, the noise of motor running. Being alone in my apartment, I made a loud cry for this glory!

On 4/7/2018 at 2:16 PM, DameVeraLynn said:

2. 12V conducting rail (looks like BL Item No: 2731b): still no luck

I cannot help with this. But I have a question. Could you tell me if you got this with your 7735 or 7745? Could you check the number written under the motor of that train with which you got this 2731b?

[DameVeraLynn]

On 09/04/2018 at 11:56 PM, Reza said:

Finally I plugged-in and turned the switch and then, the noise of motor running. Being alone in my apartment, I made a loud cry for this glory!

It is a beautiful sound to hear after all that effort!

On 09/04/2018 at 11:56 PM, Reza said:

I cannot help with this. But I have a question. Could you tell me if you got this with your 7735 or 7745? Could you check the number written under the motor of that train with which you got this 2731b?

I'm afraid I don't know for certain, as I have both 2731a (which works) and 2731b (which doesn't). It's possible that 2731b came with my 7745 and then stopped working, leading us to purchase 2731a as a replacement, but this all happened 30-odd years ago and hence I can't say with any degree of confidence. I am also unable to say which motor came with my 7745 -- see my post on your thread. Sorry I can't be of greater help!

[Reza]

15 hours ago, DameVeraLynn said:

It is a beautiful sound to hear after all that effort!

I'm afraid I don't know for certain, as I have both 2731a (which works) and 2731b (which doesn't). It's possible that 2731b came with my 7745 and then stopped working, leading us to purchase 2731a as a replacement, but this all happened 30-odd years ago and hence I can't say with any degree of confidence. I am also unable to say which motor came with my 7745 -- see my post on your thread. Sorry I can't be of greater help!

I assume that the list of motors you wrote in my thread are exactly those you had 30-odd years ago. The same assumption for your 2731a and 2731b. (are these assumptions correct?) You had two black motors 08 6 and 29 6 from 1986 and one from late 1982 (41 2) . You also had 7755, 7865 and 7745. Then 7755 comes wtih 41 2 because it was not released after 1984. Then you got two other motors in 1986 with 7865 and 7745. Their production date is close so it doesn't matter which came with which. I believe that 2731b was never sold separately. So if you didn't buy it (or were given) from a friend or a cousin, then you got 2731b with your 7745 and later you bought 2731a in a service pack. Does this sound correct?

Edited April 13, 2018 by Reza

[DameVeraLynn]

23 hours ago, Reza said:

I assume that the list of motors you wrote in my thread are exactly those you had 30-odd years ago. The same assumption for your 2731a and 2731b. (are these assumptions correct?)

Yes, all of them except the 28 81 motor, which I acquired second-hand with 7740.

23 hours ago, Reza said:

You had two black motors 08 6 and 29 6 from 1986 and one from late 1982 (41 2) . You also had 7755, 7865 and 7745. Then 7755 comes wtih 41 2 because it was not released after 1984. Then you got two other motors in 1986 with 7865 and 7745. Their production date is close so it doesn't matter which came with which. I believe that 2731b was never sold separately. So if you didn't buy it (or were given) from a friend or a cousin, then you got 2731b with your 7745 and later you bought 2731a in a service pack. Does this sound correct?

It sounds plausible, but I'm afraid there's no way I can be certain about which of 2731a and 2731b came with my 7745.